Microorganisms such as bacteria, fungi, and algae can synthesize nanoparticles either intracellularly or extracellularly. These organisms secrete specific enzymes and biomolecules that reduce metal ions into nanoparticles. For instance, bacteria can produce enzymes that facilitate the reduction of metal ions, resulting in the formation of nanoparticles in their extracellular medium. In contrast, fungi and algae often sequester metal ions inside their cells, where they are reduced and stabilized by intracellular proteins.
